There is a known method for testing a voltage to be applied to an electric load (such as an image forming unit) in an image forming apparatus. Specifically, the method is employed to determine whether the voltage is to be applied from a voltage line to the image forming unit is normal. With the method, while the voltage line is tested, a load having a lower resistance than the resistance of the image forming unit is used so that the connection between a high-voltage power source and the electric load is efficiently ascertained.
However, though the voltage line can be efficiently tested with the method, the configuration for determining pass/fail is rather complex.
Therefore, there is a need for a method for easily testing the voltage line connection of the image forming apparatus.